I checked the dip switches on the tender and they were set wrong.
Two were set to on and that caused the issue.

With these settings the loco runs fine.

forward=off
auto=on
reverse=off

I'm trying to run my #5033 Southern PS-4 with my Lionel 1033 90 watt transformer and the relay in the tender makes a clicking sound when the train starts to move causing the loco to stutter.  If I start very slowly the train will run fine until I attempt to increase the voltage at some point.  Sometimes I can get beyond this point and the loco runs fine.  Do you think this is transformer related?  It's my only transformer and it runs my Lionel fine.

Regards,
Wayne